What is a reverse DNS lookup? How can it be used when footprinting or attacking a network?
IP addresses are used for communication between devices on both internal and external networks. Because of the number of IP addresses out there, the length of IP addresses, and how many different places users travel to in one day, it is impossible to use IP addressing and remember it. The Domain Name System, or DNS, is used to translate IP addresses into domain names such as Google.com and any other internal or external place a user may visit. An example of an internal location may be //ServerA/Users/UserA/Documents. DNS uses the network layer to translate a domain name to an IP address, which then allows you to reach your destination.
Active Directory relies heavily on DNS to add and locate objects within the directory. Servers, computers, and other devices will be represented by their DNS name and not by their IP address. For Active Directory to work best, forward and reverse lookup zones must be set up on the server that hosts the domain DNS role. The forward lookup zone is used to convert hostnames into IP addresses. In the opposite sense, reverse lookup zones are configured to convert IP addresses into hostnames. At least one DNS server must be present and function in a domain for Active Directory and domain services, in general, to function correctly (Simpson, Antill, 2017).
In reverse DNS lookups, the domain name associated with a given IP address is achieved using a DNS query; both on the offensive and defensive sides of cybersecurity can significantly benefit from this action. Reverse DNS lookups can be quite valuable for mapping names and IPs for web filtering and SEO operations by deciphering what other sites a specific server hosts. In hacking, a reverse DNS lookup can provide an attacker with additional information on their target, including their geographical assignment and their ISP (IONOS, 2020).
Simpson, M. T., & Antill, N. (2017). Hands-On Ethical Hacking and Network Defense. Boston, MA. Cengage Learning.
IONOS. (2020, April 20). Reverse DNS (rDNS): Explanation and function. Retrieved March 29, 2021, from https://www.ionos.com/digitalguide/server/know-how/reverse-dns/.